* [PATCH bpf-next v2 0/2] bpf: support bpf_get_func_arg() for BPF_TRACE_RAW_TP
@ 2026-01-16 7:17 Menglong Dong
2026-01-16 7:17 ` [PATCH bpf-next v2 1/2] " Menglong Dong
2026-01-16 7:17 ` [PATCH bpf-next v2 2/2] selftests/bpf: test bpf_get_func_arg() for tp_btf Menglong Dong
0 siblings, 2 replies; 5+ messages in thread
From: Menglong Dong @ 2026-01-16 7:17 UTC (permalink / raw)
To: ast
Cc: daniel, john.fastabend, andrii, martin.lau, eddyz87, song,
yonghong.song, kpsingh, sdf, haoluo, jolsa, mattbobrowski,
rostedt, mhiramat, mathieu.desnoyers, bpf, linux-kernel,
linux-trace-kernel
Support bpf_get_func_arg() for BPF_TRACE_RAW_TP by getting the function
argument count from "prog->aux->attach_func_proto" during verifier inline.
Changes v2 -> v1:
* for nr_args, skip first 'void *__data' argument in btf_trace_##name
typedef
* check the result4 and result5 in the selftests
* v1: https://lore.kernel.org/bpf/20260116035024.98214-1-dongml2@chinatelecom.cn/
Menglong Dong (2):
bpf: support bpf_get_func_arg() for BPF_TRACE_RAW_TP
selftests/bpf: test bpf_get_func_arg() for tp_btf
kernel/bpf/verifier.c | 36 +++++++++++++--
kernel/trace/bpf_trace.c | 4 +-
.../bpf/prog_tests/get_func_args_test.c | 3 ++
.../selftests/bpf/progs/get_func_args_test.c | 45 +++++++++++++++++++
.../bpf/test_kmods/bpf_testmod-events.h | 10 +++++
.../selftests/bpf/test_kmods/bpf_testmod.c | 4 ++
6 files changed, 96 insertions(+), 6 deletions(-)
--
2.52.0
^ permalink raw reply [flat|nested] 5+ messages in thread
* [PATCH bpf-next v2 1/2] bpf: support bpf_get_func_arg() for BPF_TRACE_RAW_TP
2026-01-16 7:17 [PATCH bpf-next v2 0/2] bpf: support bpf_get_func_arg() for BPF_TRACE_RAW_TP Menglong Dong
@ 2026-01-16 7:17 ` Menglong Dong
2026-01-16 23:32 ` Andrii Nakryiko
2026-01-16 7:17 ` [PATCH bpf-next v2 2/2] selftests/bpf: test bpf_get_func_arg() for tp_btf Menglong Dong
1 sibling, 1 reply; 5+ messages in thread
From: Menglong Dong @ 2026-01-16 7:17 UTC (permalink / raw)
To: ast
Cc: daniel, john.fastabend, andrii, martin.lau, eddyz87, song,
yonghong.song, kpsingh, sdf, haoluo, jolsa, mattbobrowski,
rostedt, mhiramat, mathieu.desnoyers, bpf, linux-kernel,
linux-trace-kernel
For now, bpf_get_func_arg() and bpf_get_func_arg_cnt() is not supported by
the BPF_TRACE_RAW_TP, which is not convenient to get the argument of the
tracepoint, especially for the case that the position of the arguments in
a tracepoint can change.
The target tracepoint BTF type id is specified during loading time,
therefore we can get the function argument count from the function
prototype instead of the stack.
Signed-off-by: Menglong Dong <dongml2@chinatelecom.cn>
---
v2:
- for nr_args, skip first 'void *__data' argument in btf_trace_##name
typedef
---
kernel/bpf/verifier.c | 36 ++++++++++++++++++++++++++++++++----
kernel/trace/bpf_trace.c | 4 ++--
2 files changed, 34 insertions(+), 6 deletions(-)
diff --git a/kernel/bpf/verifier.c b/kernel/bpf/verifier.c
index faa1ecc1fe9d..422d35c100ff 100644
--- a/kernel/bpf/verifier.c
+++ b/kernel/bpf/verifier.c
@@ -23316,8 +23316,22 @@ static int do_misc_fixups(struct bpf_verifier_env *env)
/* Implement bpf_get_func_arg inline. */
if (prog_type == BPF_PROG_TYPE_TRACING &&
insn->imm == BPF_FUNC_get_func_arg) {
- /* Load nr_args from ctx - 8 */
- insn_buf[0] = BPF_LDX_MEM(BPF_DW, BPF_REG_0, BPF_REG_1, -8);
+ if (eatype == BPF_TRACE_RAW_TP) {
+ int nr_args;
+
+ if (!prog->aux->attach_func_proto)
+ return -EINVAL;
+ /*
+ * skip first 'void *__data' argument in btf_trace_##name
+ * typedef
+ */
+ nr_args = btf_type_vlen(prog->aux->attach_func_proto) - 1;
+ /* Save nr_args to reg0 */
+ insn_buf[0] = BPF_MOV64_IMM(BPF_REG_0, nr_args);
+ } else {
+ /* Load nr_args from ctx - 8 */
+ insn_buf[0] = BPF_LDX_MEM(BPF_DW, BPF_REG_0, BPF_REG_1, -8);
+ }
insn_buf[1] = BPF_JMP32_REG(BPF_JGE, BPF_REG_2, BPF_REG_0, 6);
insn_buf[2] = BPF_ALU64_IMM(BPF_LSH, BPF_REG_2, 3);
insn_buf[3] = BPF_ALU64_REG(BPF_ADD, BPF_REG_2, BPF_REG_1);
@@ -23369,8 +23383,22 @@ static int do_misc_fixups(struct bpf_verifier_env *env)
/* Implement get_func_arg_cnt inline. */
if (prog_type == BPF_PROG_TYPE_TRACING &&
insn->imm == BPF_FUNC_get_func_arg_cnt) {
- /* Load nr_args from ctx - 8 */
- insn_buf[0] = BPF_LDX_MEM(BPF_DW, BPF_REG_0, BPF_REG_1, -8);
+ if (eatype == BPF_TRACE_RAW_TP) {
+ int nr_args;
+
+ if (!prog->aux->attach_func_proto)
+ return -EINVAL;
+ /*
+ * skip first 'void *__data' argument in btf_trace_##name
+ * typedef
+ */
+ nr_args = btf_type_vlen(prog->aux->attach_func_proto) - 1;
+ /* Save nr_args to reg0 */
+ insn_buf[0] = BPF_MOV64_IMM(BPF_REG_0, nr_args);
+ } else {
+ /* Load nr_args from ctx - 8 */
+ insn_buf[0] = BPF_LDX_MEM(BPF_DW, BPF_REG_0, BPF_REG_1, -8);
+ }
new_prog = bpf_patch_insn_data(env, i + delta, insn_buf, 1);
if (!new_prog)
diff --git a/kernel/trace/bpf_trace.c b/kernel/trace/bpf_trace.c
index 6e076485bf70..9b1b56851d26 100644
--- a/kernel/trace/bpf_trace.c
+++ b/kernel/trace/bpf_trace.c
@@ -1734,11 +1734,11 @@ tracing_prog_func_proto(enum bpf_func_id func_id, const struct bpf_prog *prog)
case BPF_FUNC_d_path:
return &bpf_d_path_proto;
case BPF_FUNC_get_func_arg:
- return bpf_prog_has_trampoline(prog) ? &bpf_get_func_arg_proto : NULL;
+ return &bpf_get_func_arg_proto;
case BPF_FUNC_get_func_ret:
return bpf_prog_has_trampoline(prog) ? &bpf_get_func_ret_proto : NULL;
case BPF_FUNC_get_func_arg_cnt:
- return bpf_prog_has_trampoline(prog) ? &bpf_get_func_arg_cnt_proto : NULL;
+ return &bpf_get_func_arg_cnt_proto;
case BPF_FUNC_get_attach_cookie:
if (prog->type == BPF_PROG_TYPE_TRACING &&
prog->expected_attach_type == BPF_TRACE_RAW_TP)
--
2.52.0
^ permalink raw reply related [flat|nested] 5+ messages in thread
* [PATCH bpf-next v2 2/2] selftests/bpf: test bpf_get_func_arg() for tp_btf
2026-01-16 7:17 [PATCH bpf-next v2 0/2] bpf: support bpf_get_func_arg() for BPF_TRACE_RAW_TP Menglong Dong
2026-01-16 7:17 ` [PATCH bpf-next v2 1/2] " Menglong Dong
@ 2026-01-16 7:17 ` Menglong Dong
1 sibling, 0 replies; 5+ messages in thread
From: Menglong Dong @ 2026-01-16 7:17 UTC (permalink / raw)
To: ast
Cc: daniel, john.fastabend, andrii, martin.lau, eddyz87, song,
yonghong.song, kpsingh, sdf, haoluo, jolsa, mattbobrowski,
rostedt, mhiramat, mathieu.desnoyers, bpf, linux-kernel,
linux-trace-kernel
Test bpf_get_func_arg() and bpf_get_func_arg_cnt() for tp_btf. The code
is most copied from test1 and test2.
Signed-off-by: Menglong Dong <dongml2@chinatelecom.cn>
---
.../bpf/prog_tests/get_func_args_test.c | 3 ++
.../selftests/bpf/progs/get_func_args_test.c | 45 +++++++++++++++++++
.../bpf/test_kmods/bpf_testmod-events.h | 10 +++++
.../selftests/bpf/test_kmods/bpf_testmod.c | 4 ++
4 files changed, 62 insertions(+)
diff --git a/tools/testing/selftests/bpf/prog_tests/get_func_args_test.c b/tools/testing/selftests/bpf/prog_tests/get_func_args_test.c
index 64a9c95d4acf..fadee95d3ae8 100644
--- a/tools/testing/selftests/bpf/prog_tests/get_func_args_test.c
+++ b/tools/testing/selftests/bpf/prog_tests/get_func_args_test.c
@@ -33,11 +33,14 @@ void test_get_func_args_test(void)
ASSERT_EQ(topts.retval >> 16, 1, "test_run");
ASSERT_EQ(topts.retval & 0xffff, 1234 + 29, "test_run");
+ ASSERT_OK(trigger_module_test_read(1), "trigger_read");
ASSERT_EQ(skel->bss->test1_result, 1, "test1_result");
ASSERT_EQ(skel->bss->test2_result, 1, "test2_result");
ASSERT_EQ(skel->bss->test3_result, 1, "test3_result");
ASSERT_EQ(skel->bss->test4_result, 1, "test4_result");
+ ASSERT_EQ(skel->bss->test5_result, 1, "test5_result");
+ ASSERT_EQ(skel->bss->test6_result, 1, "test6_result");
cleanup:
get_func_args_test__destroy(skel);
diff --git a/tools/testing/selftests/bpf/progs/get_func_args_test.c b/tools/testing/selftests/bpf/progs/get_func_args_test.c
index e0f34a55e697..4b0dc233d498 100644
--- a/tools/testing/selftests/bpf/progs/get_func_args_test.c
+++ b/tools/testing/selftests/bpf/progs/get_func_args_test.c
@@ -121,3 +121,48 @@ int BPF_PROG(fexit_test, int _a, int *_b, int _ret)
test4_result &= err == 0 && ret == 1234;
return 0;
}
+
+__u64 test5_result = 0;
+SEC("tp_btf/bpf_testmod_fentry_test1_tp")
+int BPF_PROG(tp_test1)
+{
+ __u64 cnt = bpf_get_func_arg_cnt(ctx);
+ __u64 a = 0, z = 0;
+ __s64 err;
+
+ test5_result = cnt == 1;
+
+ err = bpf_get_func_arg(ctx, 0, &a);
+ test5_result &= err == 0 && ((int) a == 1);
+ bpf_printk("cnt=%d a=%d\n", cnt, (int)a);
+
+ /* not valid argument */
+ err = bpf_get_func_arg(ctx, 1, &z);
+ test5_result &= err == -EINVAL;
+
+ return 0;
+}
+
+__u64 test6_result = 0;
+SEC("tp_btf/bpf_testmod_fentry_test2_tp")
+int BPF_PROG(tp_test2)
+{
+ __u64 cnt = bpf_get_func_arg_cnt(ctx);
+ __u64 a = 0, b = 0, z = 0;
+ __s64 err;
+
+ test6_result = cnt == 2;
+
+ /* valid arguments */
+ err = bpf_get_func_arg(ctx, 0, &a);
+ test6_result &= err == 0 && (int) a == 2;
+
+ err = bpf_get_func_arg(ctx, 1, &b);
+ test6_result &= err == 0 && b == 3;
+
+ /* not valid argument */
+ err = bpf_get_func_arg(ctx, 2, &z);
+ test6_result &= err == -EINVAL;
+
+ return 0;
+}
diff --git a/tools/testing/selftests/bpf/test_kmods/bpf_testmod-events.h b/tools/testing/selftests/bpf/test_kmods/bpf_testmod-events.h
index aeef86b3da74..45a5e41f3a92 100644
--- a/tools/testing/selftests/bpf/test_kmods/bpf_testmod-events.h
+++ b/tools/testing/selftests/bpf/test_kmods/bpf_testmod-events.h
@@ -63,6 +63,16 @@ BPF_TESTMOD_DECLARE_TRACE(bpf_testmod_test_writable_bare,
sizeof(struct bpf_testmod_test_writable_ctx)
);
+DECLARE_TRACE(bpf_testmod_fentry_test1,
+ TP_PROTO(int a),
+ TP_ARGS(a)
+);
+
+DECLARE_TRACE(bpf_testmod_fentry_test2,
+ TP_PROTO(int a, u64 b),
+ TP_ARGS(a, b)
+);
+
#endif /* _BPF_TESTMOD_EVENTS_H */
#undef TRACE_INCLUDE_PATH
diff --git a/tools/testing/selftests/bpf/test_kmods/bpf_testmod.c b/tools/testing/selftests/bpf/test_kmods/bpf_testmod.c
index bc07ce9d5477..f3698746f033 100644
--- a/tools/testing/selftests/bpf/test_kmods/bpf_testmod.c
+++ b/tools/testing/selftests/bpf/test_kmods/bpf_testmod.c
@@ -396,11 +396,15 @@ __weak noinline struct file *bpf_testmod_return_ptr(int arg)
noinline int bpf_testmod_fentry_test1(int a)
{
+ trace_bpf_testmod_fentry_test1_tp(a);
+
return a + 1;
}
noinline int bpf_testmod_fentry_test2(int a, u64 b)
{
+ trace_bpf_testmod_fentry_test2_tp(a, b);
+
return a + b;
}
--
2.52.0
^ permalink raw reply related [flat|nested] 5+ messages in thread
* Re: [PATCH bpf-next v2 1/2] bpf: support bpf_get_func_arg() for BPF_TRACE_RAW_TP
2026-01-16 7:17 ` [PATCH bpf-next v2 1/2] " Menglong Dong
@ 2026-01-16 23:32 ` Andrii Nakryiko
2026-01-17 4:43 ` Menglong Dong
0 siblings, 1 reply; 5+ messages in thread
From: Andrii Nakryiko @ 2026-01-16 23:32 UTC (permalink / raw)
To: Menglong Dong
Cc: ast, daniel, john.fastabend, andrii, martin.lau, eddyz87, song,
yonghong.song, kpsingh, sdf, haoluo, jolsa, mattbobrowski,
rostedt, mhiramat, mathieu.desnoyers, bpf, linux-kernel,
linux-trace-kernel
On Thu, Jan 15, 2026 at 11:18 PM Menglong Dong <menglong8.dong@gmail.com> wrote:
>
> For now, bpf_get_func_arg() and bpf_get_func_arg_cnt() is not supported by
> the BPF_TRACE_RAW_TP, which is not convenient to get the argument of the
> tracepoint, especially for the case that the position of the arguments in
> a tracepoint can change.
>
> The target tracepoint BTF type id is specified during loading time,
> therefore we can get the function argument count from the function
> prototype instead of the stack.
>
> Signed-off-by: Menglong Dong <dongml2@chinatelecom.cn>
> ---
> v2:
> - for nr_args, skip first 'void *__data' argument in btf_trace_##name
> typedef
> ---
> kernel/bpf/verifier.c | 36 ++++++++++++++++++++++++++++++++----
> kernel/trace/bpf_trace.c | 4 ++--
> 2 files changed, 34 insertions(+), 6 deletions(-)
>
> diff --git a/kernel/bpf/verifier.c b/kernel/bpf/verifier.c
> index faa1ecc1fe9d..422d35c100ff 100644
> --- a/kernel/bpf/verifier.c
> +++ b/kernel/bpf/verifier.c
> @@ -23316,8 +23316,22 @@ static int do_misc_fixups(struct bpf_verifier_env *env)
> /* Implement bpf_get_func_arg inline. */
> if (prog_type == BPF_PROG_TYPE_TRACING &&
> insn->imm == BPF_FUNC_get_func_arg) {
> - /* Load nr_args from ctx - 8 */
> - insn_buf[0] = BPF_LDX_MEM(BPF_DW, BPF_REG_0, BPF_REG_1, -8);
> + if (eatype == BPF_TRACE_RAW_TP) {
> + int nr_args;
> +
> + if (!prog->aux->attach_func_proto)
> + return -EINVAL;
can this happen? can we have tp_btf program without attach_func_proto
properly set?
> + /*
> + * skip first 'void *__data' argument in btf_trace_##name
> + * typedef
> + */
> + nr_args = btf_type_vlen(prog->aux->attach_func_proto) - 1;
> + /* Save nr_args to reg0 */
> + insn_buf[0] = BPF_MOV64_IMM(BPF_REG_0, nr_args);
> + } else {
> + /* Load nr_args from ctx - 8 */
> + insn_buf[0] = BPF_LDX_MEM(BPF_DW, BPF_REG_0, BPF_REG_1, -8);
> + }
> insn_buf[1] = BPF_JMP32_REG(BPF_JGE, BPF_REG_2, BPF_REG_0, 6);
> insn_buf[2] = BPF_ALU64_IMM(BPF_LSH, BPF_REG_2, 3);
> insn_buf[3] = BPF_ALU64_REG(BPF_ADD, BPF_REG_2, BPF_REG_1);
> @@ -23369,8 +23383,22 @@ static int do_misc_fixups(struct bpf_verifier_env *env)
> /* Implement get_func_arg_cnt inline. */
> if (prog_type == BPF_PROG_TYPE_TRACING &&
> insn->imm == BPF_FUNC_get_func_arg_cnt) {
> - /* Load nr_args from ctx - 8 */
> - insn_buf[0] = BPF_LDX_MEM(BPF_DW, BPF_REG_0, BPF_REG_1, -8);
> + if (eatype == BPF_TRACE_RAW_TP) {
> + int nr_args;
> +
> + if (!prog->aux->attach_func_proto)
> + return -EINVAL;
> + /*
> + * skip first 'void *__data' argument in btf_trace_##name
> + * typedef
> + */
> + nr_args = btf_type_vlen(prog->aux->attach_func_proto) - 1;
> + /* Save nr_args to reg0 */
> + insn_buf[0] = BPF_MOV64_IMM(BPF_REG_0, nr_args);
> + } else {
> + /* Load nr_args from ctx - 8 */
> + insn_buf[0] = BPF_LDX_MEM(BPF_DW, BPF_REG_0, BPF_REG_1, -8);
> + }
>
> new_prog = bpf_patch_insn_data(env, i + delta, insn_buf, 1);
> if (!new_prog)
> diff --git a/kernel/trace/bpf_trace.c b/kernel/trace/bpf_trace.c
> index 6e076485bf70..9b1b56851d26 100644
> --- a/kernel/trace/bpf_trace.c
> +++ b/kernel/trace/bpf_trace.c
> @@ -1734,11 +1734,11 @@ tracing_prog_func_proto(enum bpf_func_id func_id, const struct bpf_prog *prog)
> case BPF_FUNC_d_path:
> return &bpf_d_path_proto;
> case BPF_FUNC_get_func_arg:
> - return bpf_prog_has_trampoline(prog) ? &bpf_get_func_arg_proto : NULL;
> + return &bpf_get_func_arg_proto;
> case BPF_FUNC_get_func_ret:
> return bpf_prog_has_trampoline(prog) ? &bpf_get_func_ret_proto : NULL;
> case BPF_FUNC_get_func_arg_cnt:
> - return bpf_prog_has_trampoline(prog) ? &bpf_get_func_arg_cnt_proto : NULL;
> + return &bpf_get_func_arg_cnt_proto;
> case BPF_FUNC_get_attach_cookie:
> if (prog->type == BPF_PROG_TYPE_TRACING &&
> prog->expected_attach_type == BPF_TRACE_RAW_TP)
> --
> 2.52.0
>
^ permalink raw reply [flat|nested] 5+ messages in thread
* Re: [PATCH bpf-next v2 1/2] bpf: support bpf_get_func_arg() for BPF_TRACE_RAW_TP
2026-01-16 23:32 ` Andrii Nakryiko
@ 2026-01-17 4:43 ` Menglong Dong
0 siblings, 0 replies; 5+ messages in thread
From: Menglong Dong @ 2026-01-17 4:43 UTC (permalink / raw)
To: Menglong Dong, Andrii Nakryiko
Cc: ast, daniel, john.fastabend, andrii, martin.lau, eddyz87, song,
yonghong.song, kpsingh, sdf, haoluo, jolsa, mattbobrowski,
rostedt, mhiramat, mathieu.desnoyers, bpf, linux-kernel,
linux-trace-kernel
On 2026/1/17 07:32, Andrii Nakryiko wrote:
> On Thu, Jan 15, 2026 at 11:18 PM Menglong Dong <menglong8.dong@gmail.com> wrote:
> >
> > For now, bpf_get_func_arg() and bpf_get_func_arg_cnt() is not supported by
> > the BPF_TRACE_RAW_TP, which is not convenient to get the argument of the
> > tracepoint, especially for the case that the position of the arguments in
> > a tracepoint can change.
> >
> > The target tracepoint BTF type id is specified during loading time,
> > therefore we can get the function argument count from the function
> > prototype instead of the stack.
> >
> > Signed-off-by: Menglong Dong <dongml2@chinatelecom.cn>
> > ---
> > v2:
> > - for nr_args, skip first 'void *__data' argument in btf_trace_##name
> > typedef
> > ---
> > kernel/bpf/verifier.c | 36 ++++++++++++++++++++++++++++++++----
> > kernel/trace/bpf_trace.c | 4 ++--
> > 2 files changed, 34 insertions(+), 6 deletions(-)
> >
> > diff --git a/kernel/bpf/verifier.c b/kernel/bpf/verifier.c
> > index faa1ecc1fe9d..422d35c100ff 100644
> > --- a/kernel/bpf/verifier.c
> > +++ b/kernel/bpf/verifier.c
> > @@ -23316,8 +23316,22 @@ static int do_misc_fixups(struct bpf_verifier_env *env)
> > /* Implement bpf_get_func_arg inline. */
> > if (prog_type == BPF_PROG_TYPE_TRACING &&
> > insn->imm == BPF_FUNC_get_func_arg) {
> > - /* Load nr_args from ctx - 8 */
> > - insn_buf[0] = BPF_LDX_MEM(BPF_DW, BPF_REG_0, BPF_REG_1, -8);
> > + if (eatype == BPF_TRACE_RAW_TP) {
> > + int nr_args;
> > +
> > + if (!prog->aux->attach_func_proto)
> > + return -EINVAL;
>
> can this happen? can we have tp_btf program without attach_func_proto
> properly set?
I saw it can be NULL in some case, such as bpf2bpf. Maybe it can't
happen for tp_btf, and I'll do further analysis on this point.
Thanks!
Menglong Dong
>
> > + /*
> > + * skip first 'void *__data' argument in btf_trace_##name
> > + * typedef
> > + */
> > + nr_args = btf_type_vlen(prog->aux->attach_func_proto) - 1;
> > + /* Save nr_args to reg0 */
> > + insn_buf[0] = BPF_MOV64_IMM(BPF_REG_0, nr_args);
> > + } else {
> > + /* Load nr_args from ctx - 8 */
> > + insn_buf[0] = BPF_LDX_MEM(BPF_DW, BPF_REG_0, BPF_REG_1, -8);
> > + }
> > insn_buf[1] = BPF_JMP32_REG(BPF_JGE, BPF_REG_2, BPF_REG_0, 6);
> > insn_buf[2] = BPF_ALU64_IMM(BPF_LSH, BPF_REG_2, 3);
> > insn_buf[3] = BPF_ALU64_REG(BPF_ADD, BPF_REG_2, BPF_REG_1);
> > @@ -23369,8 +23383,22 @@ static int do_misc_fixups(struct bpf_verifier_env *env)
> > /* Implement get_func_arg_cnt inline. */
> > if (prog_type == BPF_PROG_TYPE_TRACING &&
> > insn->imm == BPF_FUNC_get_func_arg_cnt) {
> > - /* Load nr_args from ctx - 8 */
> > - insn_buf[0] = BPF_LDX_MEM(BPF_DW, BPF_REG_0, BPF_REG_1, -8);
> > + if (eatype == BPF_TRACE_RAW_TP) {
> > + int nr_args;
> > +
> > + if (!prog->aux->attach_func_proto)
> > + return -EINVAL;
> > + /*
> > + * skip first 'void *__data' argument in btf_trace_##name
> > + * typedef
> > + */
> > + nr_args = btf_type_vlen(prog->aux->attach_func_proto) - 1;
> > + /* Save nr_args to reg0 */
> > + insn_buf[0] = BPF_MOV64_IMM(BPF_REG_0, nr_args);
> > + } else {
> > + /* Load nr_args from ctx - 8 */
> > + insn_buf[0] = BPF_LDX_MEM(BPF_DW, BPF_REG_0, BPF_REG_1, -8);
> > + }
> >
> > new_prog = bpf_patch_insn_data(env, i + delta, insn_buf, 1);
> > if (!new_prog)
> > diff --git a/kernel/trace/bpf_trace.c b/kernel/trace/bpf_trace.c
> > index 6e076485bf70..9b1b56851d26 100644
> > --- a/kernel/trace/bpf_trace.c
> > +++ b/kernel/trace/bpf_trace.c
> > @@ -1734,11 +1734,11 @@ tracing_prog_func_proto(enum bpf_func_id func_id, const struct bpf_prog *prog)
> > case BPF_FUNC_d_path:
> > return &bpf_d_path_proto;
> > case BPF_FUNC_get_func_arg:
> > - return bpf_prog_has_trampoline(prog) ? &bpf_get_func_arg_proto : NULL;
> > + return &bpf_get_func_arg_proto;
> > case BPF_FUNC_get_func_ret:
> > return bpf_prog_has_trampoline(prog) ? &bpf_get_func_ret_proto : NULL;
> > case BPF_FUNC_get_func_arg_cnt:
> > - return bpf_prog_has_trampoline(prog) ? &bpf_get_func_arg_cnt_proto : NULL;
> > + return &bpf_get_func_arg_cnt_proto;
> > case BPF_FUNC_get_attach_cookie:
> > if (prog->type == BPF_PROG_TYPE_TRACING &&
> > prog->expected_attach_type == BPF_TRACE_RAW_TP)
> > --
> > 2.52.0
> >
>
>
^ permalink raw reply [flat|nested] 5+ messages in thread
end of thread, other threads:[~2026-01-17 4:44 UTC | newest]
Thread overview: 5+ messages (download: mbox.gz follow: Atom feed
-- links below jump to the message on this page --
2026-01-16 7:17 [PATCH bpf-next v2 0/2] bpf: support bpf_get_func_arg() for BPF_TRACE_RAW_TP Menglong Dong
2026-01-16 7:17 ` [PATCH bpf-next v2 1/2] " Menglong Dong
2026-01-16 23:32 ` Andrii Nakryiko
2026-01-17 4:43 ` Menglong Dong
2026-01-16 7:17 ` [PATCH bpf-next v2 2/2] selftests/bpf: test bpf_get_func_arg() for tp_btf Menglong Dong
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox